1. Technical Field
The present disclosure relates to voltage regulator circuits and, particularly, to a linear voltage regulator circuit with efficient power management capability.
2. Description of Related Art
A linear voltage regulator circuit is used to connect a voltage input terminal and a voltage output terminal. The voltage input terminal is used for receiving an external voltage, such as 1.5 volts (V). The linear voltage regulator is used to regulate the external voltage to a stabilized voltage, such as a 1.2 V stabilized voltage, and then output the stabilized voltage to an electronic device through the voltage output terminal. A conversion efficiency of the linear voltage regulator circuit is equal to the stabilized voltage (namely, an input voltage of the electronic device) divided by the external voltage, which is 1.2/1.5=80%.
However, the external voltage may be a fixed value, if the input voltage of the electronic device is decreased, such as from 1.2V to 0.8V, the conversion efficiency of the linear voltage regulator circuit is also decreased to for example, from 80% to 0.8V/1.5V=53.3%, which wastes power.